Add Algebraic Notation-based identifiers for the board spaces

[ghost]

The chessboard markup will need some identifiers so we can manage the state of the checkers pieces when they are being moved about. Let's use the standard Algebraic Notation for a chessboard to identify them: https://en.wikipedia.org/wiki/Algebraic_notation_(chess)

Please give each row a numeric id and each space an id with the appropriate algebraic notation value.

[ghost]

Nice work, @sxkosone ! Your PR for this work has been merged to master 😄